Not Applicable.
The invention relates to a system and method for the effective long-term cure of recurrent female urinary incontinence, and more particularly to a urethra stabilization and support system attached to the posterior/inferior pubic bone and a method for accomplishing this in which a hypermobile urethra is repositioned in the anatomically proper position.
The problem of recurrent female urinary incontinence, or the inability to control urination, is a major and debilitating one affecting millions of women in the United States alone. One particular type that frequently occurs in women is stress urinary incontinence, which is precipitated by coughing, straining, or heavy lifting. Mild cases may be treated by exercises involving tightening and relaxing of the perineal and gluteal muscles or by sympathomimetic drug therapy. Severe cases, however, may require surgery to correct the underlying anatomic defect. It is this surgical correction which is the subject of the present invention.
In general, continence is considered to be a function of urethral support and coaptation. For coaptation to successfully prevent or cure incontinence, the urethra must be supported and stabilized in its normal anatomic position. The female""s natural support system for the urethra is a hammock-like supportive layer composed of endopelvic fascia, the anterior vaginal wall, and the arcus tendineus (a distal attachment to the pubic bone). Weakening and elongation of the pubourethral ligaments and the arcus tendineus fascia pelvis, weakening of the endopelvic fascia and pubourethral prolapse of the anterior vaginal wall, and their complex interaction with intraabdomninal forces are all suspected to play a role in the loss of pelvic support for the urethra and subsequent hypermobility to an unnaturally low non-anatomic position, leading to urinary incontinence.
Many procedures have been devised to treat urinary incontinence with the goal of elevating the neck of the bladder to return it to a higher retropubic position. Some involve the creation of a compensatory pubovaginal sling through a variety of needle suspension procedures; others employ a suburethral mesh to act as a compensatory suburethral sling to avoid the possibility that the sutures used in the needles suspension procedures will easily tear.
Many of the needle suspension procedures involve placing sutures in the endopelvic fascia or the anterior vaginal wall on either side of the urethra and attaching them to fixation sites such as bone and soft tissue. Alternatively, the sutures are attached to artificial anchors placed within the pelvis, at the superior border of the pubis, or rectus abdominus fascia. A major problem with this type of procedure is that the very fascial and muscular support structures that are sutured for support are often stretched, damaged, or otherwise deficient to begin with, and remain so after the procedure. It is therefore difficult to employ them successfully as reinforcements for surgical repair.
The pubovaginal sling procedure, in which a mesh is placed under the urethra to provide elevation and support of the urethra and bladder neck, is performed through an abdominal incision, and has enjoyed an excellent surgical success rate. It is generally preferable for more complicated cases of recurrent genuine stress urinary incontinence, particularly in patients who have failed prior surgery, who are obese, or whose lifestyles involve heavy lifting and accompanying increased intraabdominal pressure. However, problems with voiding disjunction and urinar retention, detrusor instability, and infection and erosion of sling materials that can lead to urethrovesical and vesicovaginal fistulas are cause for concern. Additionally, because of the abdominal incision, this procedure is more technically challenging, presents greater blood loss, longer operative time, and a prolonged postoperative recovery.
These techniques use a variety of attachment sites for bladder neck and urethral support, such as the superior portion of the pubis, Cooper""s ligament, or rectus abdominus fascia. This results in placement of the urethra in an unnaturally high position with respect to its normal anatomical retropubic position so that problems with voiding and retention frequently arise after the procedure. Further, this abnormal positioning of the urethra in conjunction with failure of the supporting tissues and poor surgical technique have often led to a recurrence of incontinence since all of these operations create a compensatory abnormality rather than restoring the normal anatomy.
A related difficulty that contributes to the unnatural positioning of the urethra is that some attachment sites, such as the rectus abdomninus fascia, require very long sutures and accompanying difficulty in achieving the proper tension in the sutures. This can result in increased lateral movement and momentum of the support structures or mesh sling when they are moved due to intraabdominal pressures.
The present invention addresses and corrects these and other difficulties by affecting the continence mechanism directly and providing a predictable and lasting permanent cure for the problem of recurrent female urinary incontinence.
It has been found that the key site for control of continence has not been heretofore addressed. It has further been found that the urethral hypermobility observed in most incontinent patients is caused by a lax or torn arcus tendineus facie pelvis attachment at its origin near the anterior levator arch in the immediate retropubic position at the site of the pubourethral ligaments. Repair and reinforcement of this area to stabilize the urethra in its normal position may be equally important as repair of the endopelvic facie. Therefore, the key site for control of continence is the paraurethral attachments of the pubourethral ligaments to the sides of the urethra at the intermediate 60% of the urethral length. This is simulated through the employment of a mesh sling system which supports this site and restores the bladder neck and urethra to their normal anatomic retropubic position. Additionally, when placed in this position, the lateral sides of the mesh serve to act as pubourethral ligaments which help to prevent undue descent of the urethra.
It has also been found that although the superior portion of the pubic bone is a functional and secure fixation site for incontinence repair, a key to restoring the urethra to its normal anatomical position is using the posterior/inferior border of the pubic bone, not the superior portion, as the attachment sites for the mesh sling system. In particular, the sling system is anchored to the pubic bone near the point of attachment of the arcus tendineus to the pubic bone. Proper tensioning of the mesh sling system is made easier by using this portion of the pubic bone as the attachment site, due in part to the fact that shorter sutures and an innovative mesh suturing pattern is used. This serves to avoid the problems heretofore discussed associated with an improperly high retropubic positioning of the urethra.
According to the invention there is provided a pubic bone-mounted urethra stabilization and support system and a method for the long term cure of recurrent female urinary incontinence.
The system comprises a pair of anchors which are affixed to the posterior/inferior pubic bone near the point of attachment of the arcus tendineus to the pubic bone, sutures attached to the anchors, and a sling which is passed behind and about the urethra and the adjacent endopelvic fascia Ends of the sling are attached to the anchors by the anchor-mounted sutures. In particular, a pair of anchor screws are located on either side of the symphysis pubis in the retropubic area posteriorly and at about 0.5 cm superiorly of the inferior edge of the ischial ramus. Sutures connect the anchor screws to the mesh sling. The mesh sling directly supports the urethra by its placement on the endopelvic fascia in the area of the intermediate 60 percent portion of the urethra as will be later described in greater detail.
The method includes the steps of accessing said urethra and pubic bone, properly locating and attaching the anchors to the pubic bone, properly locating the sling about the urethra and suturing and tensioning the ends of the sling to the anchors, causing said sling to restore, support and stabilize functional urethral continence anatomy and prevent urethral descent under intraabdominal pressure.
To access the urethra and pubic bone, a pair of divergent incisions are made, beginning at the posterior urethral fold, in the anterior vaginal wall. This creates a triangular flap to expose the operative field. Care must be taken to separate the anterior vaginal wall from the adjoining endopelvic fascia to leave the endopelvic fascia intact. Direct visualization and palpation is next employed to evaluate the integrity of the lateral attachment of the endopelvic fascia to each arcus tendineus fascia pelvis, repairing any damage by suturing if necessary.
The pubic bone is next located by palpation. The course of the arcus from the ischial spine to the arcus insertion into the posterior/inferior aspect of the pubic bone is palpated to locate the proper site for the anchor screws, which is at either side of the symphysis pubis in the retropubic area posteriorly and at about 0.5 cm superiorly of the inferior edge of the ischial ramus. An anchor screw, which is provided with a pair of permanent sutures, is driven into the pubic bone at this location and set. An identical anchor screw is then driven into a symmetrically located position on the other side of the symnphysis pubis.
A sling, which can be made of a substantially rectangular patch of surgical mesh, is next laid upon the endopelvic fascia such that its longitudinal edges extend transversely of the urethra which is below the endopelvic fascia. Four permanent sutures are used to transfix the mesh along the lateral borders of the urethra at the edges of the mesh. These sutures are so positioned as to create a slight trough-like space between the mesh and the endopelvic fascia and urethra. This space prevents undue tension on the urethra by the mesh when the mesh is formed into a sling. The permanent sutures of the anchor screws are then woven transversely of the mesh in opposite directions between the longitudinal edges of the mesh and inset from the transverse mesh edges. These sutures are then bilaterally tied with appropriate tensioning to transform the mesh into a sling.
Finally, any additional necessary repairs, including the sequential tying of the repair sutures for attaching the endopelvic fascia to the arcus tendineus fascia pelvis, are made. The cut edges of the anterior vaginal wall are approximated with sutures, and the cul-de-sac and posterior vaginal segment defects are repaired.
The bone anchor can either be a bone screw or a harpoon-type anchor. If the bone anchor is a screw, it is preferably implanted using a bone drill, such as disclosed in WO 97/30638. If a harpoon-type bone anchor is used, a transvaginal bone anchor implantation device of the present invention is preferably used. The bone anchor implantation device of the present invention comprises a shaft or body having a grip at a first end of the shaft, an anchor mount at a distal end of the shaft, and a bone anchor removably mounted in the anchor mount. The shaft is preferably bent so that the anchor mount generally faces the grip such that the bone anchor can be implanted at an anchoring site in a bone by pulling rearwardly on the device. The body is adapted to be separable from the anchor after the anchor has been implanted in bone.
A suture thread is attached to the bone anchor such that the suture thread is accessible to a surgeon using the device after the bone anchor has been implanted in bone and after the body has been separated from the bone anchor. The shaft is at least partially hollow, and the suture thread is housed in the shaft. The anchor mount comprises a cannula at the distal end of the shaft. The cannula being sized to removably receive an end of the anchor.
In use, the procedure is substantially the same as described above. The only difference lies in the method in which the bone anchor is inserted into the bone. Once the anchor site is located, the device is introduced into the patient transvaginally through the vaginal wall incision. The anchor is placed at the anchor site on the pubic bone, and the device is pulled to drive the anchor into the pubic bone. Once the anchor has been implanted, the shaft is separated from the anchor and removed from the patient.
is hook shaped.